Espritmodel.com Telemetry Radio
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Old Mar 11, 2013, 01:04 PM
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hey.. that is super cool. i specially like those servo pads. hard to get smaller than that. and looks like same size as a7105 module. where did you get those made? seeed studio?
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Old Mar 11, 2013, 01:30 PM
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Sorry should have added more details. Thats the backside of the A7105 module.
I epoxied copper tracks i pre-etched, not complete yet got 2 more tracks to add.
Could be simpler way to make your milligram RX, maybe more compacted. I'm hoping to do 8ch something like what you did. Do you have link to pdf with circuit or page number ?
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Last edited by SadSack; Mar 11, 2013 at 01:36 PM.
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Old Mar 11, 2013, 01:36 PM
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yeah, i recognized the ground pad vias. how big is it? did you make that board yourself or send out?
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Old Mar 11, 2013, 01:38 PM
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and more to the point would your 8ch code do milligram ?
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Old Mar 11, 2013, 01:43 PM
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did it myself...wouldn't be any fun letting someone do it better than me
Don't know if its a new idea but started doing simple stuff like pads on top of tqfp for programming pads ie esc that don't have them. Other things it could do would with it would be adding resonator pads so could add what ever clock speed and still do deadbug simple. To many ideas in my head what it could be used for...
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Old Mar 11, 2013, 01:46 PM
RC beginner
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Quote:
Originally Posted by SadSack View Post
and more to the point would your 8ch code do milligram ?
yes, as long as you use mega8 smd.

oh no... dont tell me that is the actual back of an off the shelf module. i thought it was your own new pc board but this is a whole new method. how did you keep from etching away all the components on top? this just keeps getting more and more interesting.
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Old Mar 11, 2013, 01:55 PM
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Quote:
Originally Posted by dave1993 View Post
yes, as long as you use mega8 smd.

oh no... dont tell me that is the actual back of an off the shelf module. i thought it was your own new pc board but this is a whole new method. how did you keep from etching away all the components on top? this just keeps getting more and more interesting.
Excellent need more modules!!!
Thank you kindly



thats 6th go just hope it works, soldering is next !
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Old Mar 11, 2013, 02:10 PM
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Quote:
Originally Posted by SadSack View Post
I epoxied copper tracks i pre-etched, not complete yet got 2 more tracks to add.
pre-etched? and looks like two layers? im still not sure whats going on there. do you start with super thin fr4?

Quote:
Originally Posted by SadSack View Post
Could be simpler way to make your milligram RX, maybe more compacted. I'm hoping to do 8ch something like what you did. Do you have link to pdf with circuit or page number ?
maybe not more compacted because using orginal module weighs more than couple grams. but definitely easier than hand soldering the way i do it now. of course ANYTHING is easier than the deadbug. orders of magnitude easier, no exaggeration.

pdf is too big for rcgroups so i added a link to it in post #1 too. http://www.avantcom.com.tw/AVANTCOM/...SOLVE/18_3.pdf
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Last edited by dave1993; Mar 11, 2013 at 02:22 PM. Reason: pdf link
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Old Mar 11, 2013, 02:42 PM
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Materials i use :
Sellotape works very well. Don't use cheap packing tape its cost me a lot of time and not as turn out as well as i've done in the past.
Copper Foil tape very cheap.First put Sellotape on copper, no bubble and smooth. I then remove adhesive with cellulose thinners. Put paper towel on sticky bit then soak it with small amount thinners leave for latest 10 mins longer better, don't let it dry out keep wet as needed. adhesive will turn to jelly. Then i rub it off using Stanley blade, if your scraping it off soak it longer.
Then etch in the normal way.
Then i mix half hour epoxy (not 5min) small amount on pcb rub it around just to make it sticky then using Stanley blade put more tape/foil enough that is just glossy and not so much you can dent it its so thick.
When it dry enough tape will just peel off like coming off glass but when wet glue will grab hold of tape.

Some pictures maybe better, not great ones mind





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Old Mar 11, 2013, 02:45 PM
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Thanks for link...i will get to it once this is working again.
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Old Mar 11, 2013, 02:58 PM
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this is insane. i must try it. do i understand?

1. put sellotape on non-sticky side of guitar shielding copper tape.
2. remove copper tapes adhesive.
3. etch
4. epoxy copper side to pcb.
5. peel off sellotape.

do i have this right? did i mention this is insane?
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Old Mar 11, 2013, 03:42 PM
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SadSack, that is completely brilliant, you've got me thinking of all sorts of possibilities.

dave1993, I love the brutal trimming of the ref circuit for the deadbug, any chance of seeing the details?
Alan
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Old Mar 11, 2013, 06:42 PM
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yes, when i get a chance ill peek under the hood of the deadbug and see whats there. fortunately its built flip top style with tiny piece of foam tape hinging it together. iirc in addition to a big vcc decoupling cap there was a bypass cap for the internal ldo and another one with resistor to set pll time constant. section 20.0 of the manual has the schematic i worked from. i just kept pulling legs off the bug till it couldnt walk anymore then put one back on.
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Last edited by dave1993; Mar 11, 2013 at 07:27 PM. Reason: section 20.0 of the manual not section 2.0 of the maunal
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Old Mar 11, 2013, 07:16 PM
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SadSack I always wondered how you made those perfect little copper tracks on your Mega8's.

Never came around to ask, now I know.

That is a marvelous work of art and patience.

Beautiful craftsmanship.

Thank you for sharing, even tough I am not patient enough nor I have the skill to do the same.

But, I did thought about gluing the M8 to the back of the module and doing the tracks with conductive silver paint.

Did I mention I have no patience for that kind of meticulous work ? (it stays at the dream stage)

Btw, how much does the A7105 module weighs ?

Cheers mate
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Old Mar 11, 2013, 08:02 PM
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Quote:
Originally Posted by dave1993 View Post
this is insane. i must try it. do i understand?

1. put sellotape on non-sticky side of guitar shielding copper tape.
2. remove copper tapes adhesive.
3. etch
4. epoxy copper side to pcb.
5. peel off sellotape.

do i have this right? did i mention this is insane?
LOL yup pretty much and rest you'll work out. Copper tape is a very thin copper, etch's very fast mind. When i looked i found a guy in US selling thicker but want some insane shipping like $40 + If i remember right pretty sure copper was very cheap. And epoxy getting right amount, if it floats about easy you have far to much on. When it's right quite hard to move around and end's up very flat.
When doing printing in eagle (if you use that) don't invert top layer, print as it should look. Bottom that will need flipping to be right. Doing it onto pcb it's other way round as I'm sure you know.

Quote:
Originally Posted by Alan Hopper View Post
SadSack, that is completely brilliant, you've got me thinking of all sorts of possibilities.

dave1993, I love the brutal trimming of the ref circuit for the deadbug, any chance of seeing the details?
Alan
If you replace sellotape with this you could make solderable ribbon cables....

Quote:
Originally Posted by blackmoon View Post
SadSack I always wondered how you made those perfect little copper tracks on your Mega8's.

Never came around to ask, now I know.

That is a marvelous work of art and patience.

Beautiful craftsmanship.

Thank you for sharing, even tough I am not patient enough nor I have the skill to do the same.

But, I did thought about gluing the M8 to the back of the module and doing the tracks with conductive silver paint.

Did I mention I have no patience for that kind of meticulous work ? (it stays at the dream stage)

Btw, how much does the A7105 module weighs ?

Cheers mate
Easy tiger! If you want to go on a date? Just ask LOL btw only joking

Thank you too kind but afraid Dave does the real magic here. What i know about coding i could maybe write in space left on module
And trust me this is easier than you think and no special tooling and you most likely all ready have. Can pull small pieces copper off ground planes or even pcb what i did for ESC's.
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